Tuesday 9 March 2010 19.48 EST
First published on Tuesday 9 March 2010 19.48 EST

Britain will today urge the Afghan government to put more effort into the pursuit of peace talks amid fears that the war could be prolonged – and more British lives lost – as a result of incompetence and lack of political will in Kabul.

A speech to be delivered in the US by the foreign secretary, David Miliband, will reflect growing anxiety in London that President Hamid Karzai's professed desire for a political solution has not been backed up by any serious planning or concrete proposals.

Unless more pressure is put on the Afghan government, some British officials predict that Karzai's proposed loya jirga, or grand peace council, due at the end of next month, will be little more than a PR stunt. "My argument today is that now is the time for the Afghans to pursue a political settlement with as much vigour and energy as we are pursuing the military and civilian effort," Miliband will say at the Massachusetts Institute of Technology, according to a text of the address seen by the Guardian.

British officials believe that significant Taliban leaders are ready to start talking about a political settlement in which they would sever ties with al-Qaida and put down weapons in return for a role in politics. But there is also concern that opportunities to open a preliminary dialogue are being lost, and that the conflict, which has already cost more than 270 British lives, is being intensified by Kabul's inefficiency and corruption.

"The Afghans must own, lead and drive such political engagement," Miliband will say in his speech. "It will be a slow, gradual process. But the insurgents will want to see international support.

"International engagement, for example under the auspices of the UN, may ultimately be required."

Karzai presented a paper on political reconciliation at a conference held by Gordon Brown in London in January. But officials who saw it, and subsequent Afghan proposals on peace talks, have variously described them as "empty" and "a C-team effort".

Gerard Russell, at the Carr Centre for Human Rights at Harvard University, said: "We had a look at the Afghan government's thinking on reconciliation, but we haven't seen a concrete proposal or a workable methodology."

Russell, a former political adviser to the UN mission in Afghanistan, added: "There is a talk about having a loya jirga. But what is a loya jirga going to do? On its own, its not going to achieve anything."

The growing alarm at the lack of political initiative in Kabul comes at a time when back-channel contacts with the Taliban have also run into trouble, paradoxically as a result of a Taliban arrest hailed as a triumph last month.

Mullah Abdul Ghani Baradar, the head of the Taliban's military operations seized in Karachi by Pakistani intelligence agents, had taken part in tentative and secret contacts with Saudi intermediaries last year.

One participant in those talks told the Guardian that Baradar's arrest had been "a huge blow" to the peace effort.

Britain's special envoy for Afghanistan and Pakistan, Sir Sherard Cowper-Coles, has been sent to Kabul as caretaker ambassador, with the primary mission of trying to inject more substance into the loya jirga planned for 29 April. Tomorrow, Miliband will also call for a direct international role in managing the peace process. Miliband's speech also carries a message for Washington.

While Britain's Foreign Office believes work on peace talks should begin straight away and be pushed behind the scenes by the Obama administration, most US officials, and some British generals, question whether such negotiations would produce results before Taliban morale has been depleted by the military surge.

"There is an important US audience for this," a British official said. "Nobody wants a PR stunt in Kabul that doesn't lead anywhere."